multinode: dns not working for pods on nodes where CoreDNS is not present

[prezha]

example:

failing "TestMultiNode/serial/DeployApp2Nodes" test log extract (from https://storage.googleapis.com/minikube-builds/logs/10792/4e34b35/KVM_Linux.html#fail_TestMultiNode%2fserial%2fDeployApp2Nodes):

...
multinode_test.go:426: (dbg) Run:  out/minikube-linux-amd64 kubectl -p multinode-20210329232030-517232 -- exec hello-f45cbcf6d-4q7vp nslookup kubernetes.io
multinode_test.go:426: (dbg) Non-zero exit: out/minikube-linux-amd64 kubectl -p multinode-20210329232030-517232 -- exec hello-f45cbcf6d-4q7vp nslookup kubernetes.io: exit status 1 (5.278758422s)
-- stdout --
-- /stdout --
** stderr ** 
	kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
	nslookup: can't resolve '(null)': Name does not resolve
	nslookup: can't resolve 'kubernetes.io': Try again
	command terminated with exit code 1
** /stderr **
multinode_test.go:428: Pod hello-f45cbcf6d-4q7vp could not resolve 'kubernetes.io': exit status 1

multinode_test.go:426: (dbg) Run:  out/minikube-linux-amd64 kubectl -p multinode-20210329232030-517232 -- exec hello-f45cbcf6d-f7hgg nslookup kubernetes.io
multinode_test.go:426: (dbg) Non-zero exit: out/minikube-linux-amd64 kubectl -p multinode-20210329232030-517232 -- exec hello-f45cbcf6d-f7hgg nslookup kubernetes.io: exit status 1 (5.254324315s)
-- stdout --
-- /stdout --
** stderr ** 
	kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
	nslookup: can't resolve '(null)': Name does not resolve
	nslookup: can't resolve 'kubernetes.io': Try again
	command terminated with exit code 1
** /stderr **
multinode_test.go:428: Pod hello-f45cbcf6d-f7hgg could not resolve 'kubernetes.io': exit status 1
...

/assign